R: Income distribution (percentages) in the Northeast US
income
R Documentation
Income distribution (percentages) in the Northeast US
Description
Income distribution (percentages) in the Northeast US in 1960 and 1970
adopted from McCullagh (1980).
Usage
income
Format
year
year.
pct
percentage of population in income class per year.
income
income groups. The unit is thousands of constant (1973) US dollars.
Source
Data are adopted from McCullagh (1980).
References
McCullagh, P. (1980) Regression Models for Ordinal Data. Journal
of the Royal Statistical Society. Series B (Methodological),
Vol. 42, No. 2., pp. 109-142.
Examples
print(income)
## Convenient table:
(tab <- xtabs(pct ~ year + income, income))
## small rounding error in 1970:
rowSums(tab)
## compare link functions via the log-likelihood:
links <- c("logit", "probit", "cloglog", "loglog", "cauchit")
sapply(links, function(link) {
clm(income ~ year, data=income, weights=pct, link=link)$logLik })
## a heavy tailed (cauchy) or left skew (cloglog) latent distribution
## is fitting best.
## The data are defined as:
income.levels <- c(0, 3, 5, 7, 10, 12, 15)
income <- paste(income.levels, c(rep("-", 6), "+"),
c(income.levels[-1], ""), sep = "")
income <-
data.frame(year=factor(rep(c("1960", "1970"), each = 7)),
pct = c(6.5, 8.2, 11.3, 23.5, 15.6, 12.7, 22.2,
4.3, 6, 7.7, 13.2, 10.5, 16.3, 42.1),
income=factor(rep(income, 2), ordered=TRUE,
levels=income))